Additives For Removal Of Metals Poisonous To Catalysts During Fluidized Catalytic Cracking Of Hydrocarbons

ABSTRACT

Compositions and methods suitable for removing poisonous metals from hydrocarbons are provided. The compositions comprise hydrotalcite having one or more trapping metals dispersed on the outer surface thereof.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation of copending U.S. application Ser.No. 11/771,826, filed Jun. 29, 2007, which is incorporated herein byreference.

BACKGROUND

One major operation in the modern refinery is the process of catalyticcracking. In this process, some of the heavier oils (often called “gasoils”) produced upon fractionation of whole crude oil are decomposed or“cracked” using fluidized zeolite-containing catalysts.

As the supply of light, sweet crude oils has dwindled during past years,catalytic cracking has become increasingly important in maintaining asupply of hydrocarbons suitable for use in various fuels such asgasoline. A problem that has occurred because of the increasing use ofheavier, more sour crudes is that the heavier crudes containsubstantially more organic metal compounds, such as vanadium and nickelporphyrins. These metals cause many undesirable reactions in heavy oilcracking in that the metals, specifically nickel and vanadium, are quiteharmful to the fluidized cracking catalysts used. These metals, presentin the high-boiling fractions, deposit on cracking catalyst andaccumulate with time. They act as poisons and have the resulting effectof increasing undesirable hydrogen and coke yields, decreasing theselectivity of the catalyst in making liquid products. It is alsoestablished that vanadium also attacks the zeolite itself, the highactivity component of a catalytic cracking catalyst.

Much effort has been made by those in the refinery/refinery catalystindustry to attempt to deal with the problem of vanadium and othermetals poisonous to zeolite-containing catalysts during fluidizedcatalytic cracking (FCC). U.S. Pat. No. 6,610,255 describes manytechnologies that have been proposed. The vast majority of thesetechnologies deal with the addition of so-called “trapping agents”,either with the catalyst or with the hydrocarbon feed; and thesetrapping agents, such as barium, calcium, and strontium have been shownto reduce the deleterious effects of poisonous metals onzeolite-containing FCC catalysts.

In spite of recent developments in FCC catalyst technology, a need stillexists for a commercially feasible means for introducing trapping agentsduring FCC for effectively removing vanadium and other poisonous metalsfrom hydrocarbons.

THE INVENTION

This invention fulfills the current need by providing compositions andmethods suitable for removing one or more poisonous metals fromhydrocarbons. Compositions according to this invention comprisehydrotalcite (HTC) having one or more trapping metals dispersed on theouter surface thereof. Methods for removing one or more poisonous metalsfrom hydrocarbons in an FCC unit according to this invention compriseadding to the FCC unit hydrotalcite having one or more trapping metalsdispersed on the outer surface thereof. In some embodiments of thisinvention, compositions of this invention consist essentially of, orconsist of, hydrotalcite having at least one trapping metal dispersed onthe outer surface thereof. Using HTC as a carrier for one or moretrapping agents dispersed thereon provides good contact betweenpoisonous metals and trapping agents.

While this invention will be described in connection with specificembodiments, it is understood that this invention is not limited to anyone of these specific embodiments.

Hydrotalcite

Any hydrotalcite can be used in the present invention. The hydrotalcitecan comprise (a) naturally occurring hydrotalcite, (b) synthetichydrotalcite, (c) a hydrotalcite-like material, or (d) a mixture of anytwo or more of (a)-(c). Suitable hydrotalcite carriers are described inU.S. Pat. Nos. 4,347,353 and 4,284,762. Suitable hydrotalcite carriersinclude mixed metal oxides of CaO, MgO, and Al2O3, for examples. Onesuitable hydrotalcite has a chemical formula ofMg_(4.5)Al₂(OH)₁₃CO₃.3.5H₂O, Suitable hydrotalcite materials aremanufactured by Kyowa Chemical Industry Company, Ltd., Osaka, Japan, andare marketed by Mitsui and Company, Ltd., Osaka, Japan, and by Mitsuiand Company (USA), Inc., Houston, Tex., under the product designationsof “DHT-4” and “DHT-4A”.

Hydrotalcite-Like Materials and Methods of Making Same

Crystalline anionic clays, including, meixnerite, sjogrenite,pyroaurite, stichtite, reevesite, eardleyite, manassite, andbarbertonite, are hydrotalcite-like materials according to thisinvention. For most commercial applications crystalline anionic claysare formed into shaped bodies such as spheres. In applications whereshaped bodies are exposed to severe processing conditions andenvironments, such as oil refinery applications, separations,purifications, and absorption processes, it is important that theintegrity of the crystalline anionic clay-containing shaped bodies iskept intact and attrition is prevented. A process for the preparation ofcrystalline anionic clay-containing bodies from sources comprising analuminum source and a magnesium source comprises the steps of: a)preparing a precursor mixture, b) shaping the precursor mixture toobtain shaped-bodies, c) optionally thermally treating the shapedbodies, and d) aging to obtain crystalline anionic clay-containingbodies. The shaped bodies can be prepared in various ways. In oneembodiment, an aluminum source and a magnesium source are combined in aslurry to form a precursor mixture. Subsequently, said precursor mixtureis shaped. The resulting shaped bodies are aged, optionally afterthermal treatment, in a liquid to obtain crystalline anionicclay-containing bodies.

It is also possible to prepare a precursor mixture from only one sourcesuch as an aluminum source or a magnesium source, shape it, and then addone or more additional other sources to the shaped bodies in any of thesubsequent process steps. During the aging step, the various sourcesreact to give the crystalline anionic clay-containing bodies. Of course,it is also possible to use combinations of the two preparation routesdescribed above, for instance: add; the aluminum source and themagnesium source to form the precursor mixture, shape to form bodies,and then age the shaped bodies in a liquid containing additionalmagnesium source to form anionic clay-containing bodies with a highermagnesium content on the outside of the shaped body.

Suitable alumina sources include aluminum oxides and hydroxides such astransition alumina, aluminum trihydrate (gibbsite, bayerite) and itsthermally treated forms (including flash calcined alumina), sols,amorphous alumina, (pseudo)boehmite, aluminum-containing clays such askaolin, sepiolite, hydrotalcite, and bentonite, modified clays such asmetakaolin, alumina salts such as aluminum nitrate, aluminum chloride,aluminum chlorohydrate, sodium aluminate. With the preparation methodsdescribed herein it is also possible to use cruder grades of aluminumtrihydrate such as BOC (Bauxite Ore Concentrate) or bauxite. When claysare used as an Al-source, it may be necessary to activate the alumina inthe clay by acid or base treatment, for instance acid-treated bentonite,(hydro)thermal treatment, or combinations thereof. Acid treatmentcomprises treatment with nitric acid, acetic acid, phosphoric acid,sulfuric acid, hydrochloric acid, and the like. Thermal treatment isusually performed at temperatures ranging from 30° C. to 1000° C.,sometimes from 200° C. to 800° C., for a time ranging from severalminutes to 24 hours, sometimes from 1-10 hours. Also mixtures of theabove-mentioned aluminum sources can be used, and said differentaluminum sources can be combined in the precursor mixture in anysequence. It is also possible to add an aluminum source after theshaping step. In that case, the precursor mixture may or may not alreadycontain an aluminum source. In one embodiment, if an aluminum source isadded after the shaping step, it is in liquid when contacted with theshaped bodies. This can be done by dispersing or dissolving the aluminumsource and adding it to the shaped bodies. Alternatively, the aluminumsource can be added to the liquid in which the shaped bodies are aged.

Also, other aluminum sources than clay, such as aluminum trihydrate, maybe pre-treated prior to the addition to the precursor mixture or priorto contacting it with the shaped bodies. Said pre-treatment may involvetreatment with acid, base treatment, thermal and/or hydrothermaltreatment, all optionally in the presence of seeds or combinationsthereof. It is not necessary to convert all of the aluminum source intocrystalline anionic clay. Any excess aluminum will be converted intosilica-alumina, alumina (usually in the form of γ-alumina or(crystalline) boehmite) and/or alumina-magnesia during the aging step.These compounds improve the binding properties of the shaped bodies andmay also provide different types of desirable functionalities for thebodies. For instance, silica-alumina and alumina provide acid sites forcatalytic cracking and alumina (crystalline) boehmite also improves thenickel encapsulation capacity of the shaped bodies. The formation of,for example, (crystalline) boehmite may be promoted by adding seeds,either in the precursor mixture, in the aluminum source or during aging.

Suitable magnesium sources include magnesium oxides or hydroxides suchas MgO, Mg(OH)₂, hydromagnesite, magnesium salts such as magnesiumacetate, magnesium formate, magnesium hydroxy acetate, magnesiumcarbonate, magnesium hydroxy carbonate, magnesium bicarbonate, magnesiumnitrate, magnesium chloride, magnesium-containing clays such asdolomite, saponite, sepiolite. Also mixtures of the above-mentionedmagnesium sources can be used, and said different magnesium sources canbe combined in the precursor mixture in any sequence and/or in anyprocess step after the shaping step. In one embodiment, if a magnesiumsource is added after the shaping step, it is in liquid when contactedwith the shaped bodies. This can be done by dispersing or dissolving themagnesium source and adding it to the shaped bodies. Alternatively, themagnesium source can be added to the liquid in which the shaped bodiesare aged.

The magnesium source may be pre-treated prior to the addition to theprecursor mixture and/or prior to the addition to the shaped bodies.Said pretreatment may comprise a thermal and/or a hydrothermaltreatment, an acid treatment, a base treatment, all optionally in thepresence of a seed, and/or combinations thereof.

It is not necessary to convert all of the magnesium source intocrystalline anionic clay. Any excess magnesium will usually be convertedinto brucite, magnesia or alumina-magnesia. For the sake of clarity,this excess of magnesium compounds in the shaped particle will bereferred to in the description as magnesia. The presence of magnesia oralumina-magnesia in the shaped body may provide desirablefunctionalities to the shaped bodies. The presence of magnesia providesbasic sites that render the shaped body suitable for removing orneutralizing strong acid streams of gases or liquids.

The various process steps will be described in more detail below.

Hydrotalcite-Like Materials and Methods of Making Same—Preparation ofthe Precursor Mixture

In this step a precursor mixture is prepared from an aluminum sourceand/or a magnesium source in a liquid. In fact, all liquids aresuitable, as long as they do not detrimentally interfere with thevarious sources. Suitable liquids are water, ethanol, propanol, and thelike. The amount of liquid can be chosen such that a mixture with amilky substance is obtained, but also mixtures with a higher viscosity,for instance doughs, are suitable. If more than one source is used forthe precursor mixture, the sources can be added as solids, but they canalso be added in liquid. The various sources can be added in anysequence. The preparation of the precursor mixture can be carried outwith or without stirring, at room temperature or elevated temperature.Optionally, the precursor mixture and/or the separate sources arehomogenized by, for instance, milling. Some conversion to crystallineanionic clay may already take place upon combining the various sources.In some instances, at least about 5 wt % of the final total amount ofanionic clay is already formed, and in some instances conversion alsotakes place after the shaping step. In other instances more than about25 wt %, or more than about 50 wt %, or more than about 75 wt %, orbetween about 80 to about 95 wt % of the final amount of anionic clay inthe shaped body is formed after the shaping step. The Mg:Al ratio mayvary, e.g., from about 1 to about 10, from about 1 to about 6, or fromabout 2 to about 4.

If desired, organic or inorganic acids and bases, for example forcontrol of the pH, may be added to the precursor mixture or added to anyone of the aluminum source and/or magnesium source before these areadded to the precursor mixture. When an ammonium base modifier is used,upon drying, no deleterious cations remain in the anionic clay. Theprecursor mixture may be preaged prior to the shaping step. Saidpre-aging temperature may range from about 30° C. to about 500° C. andmay be conducted under atmospheric or increased pressure such asautogeneous pressure at temperatures above about 100° C. The aging timecan vary from about 1 minute to several days, for instance about 7 days.By adding specific anions to the precursor mixture and/or any of thealuminum and or magnesium source the interlayer-charge balancing anionspresent may be controlled. Examples of suitable anions are carbonates,bicarbonates, nitrates, chlorides, sulfates, bisulfate's, vanadates,tungstates, borates, phosphates, pillaring anions such as V10O28-6,Mo7O24-6, PW12O40-3, B(OH)4-, B4O5(OH)4-2, HBO4-2, HGaO3-2, CrO4-2formates, acetate, and mixtures thereof. It is also believed that thepresence of some of these anions such as carbonate, bicarbonate, sulfateand or nitrate influences the forming of side products such as brucite.For instance, the addition of ammonium hydroxide promotes meixneriteformation, whereas the addition of ammonium carbonate promoteshydrotalcite formation.

Hydrotalcite-Like Materials and Methods of Making Same—Shaping

Suitable shaping methods include spray-drying, pelletising, extrusion(optionally combined with kneading), beading, or any other conventionalshaping method used in the catalyst and absorbent fields or combinationsthereof. The amount of liquid present in the precursor mixture used forshaping should be adapted to the specific shaping step to be conducted.It is sometimes advisable to (partially) remove the liquid used in theprecursor mixture and/or add additional or other liquid, and/or changethe pH of the precursor mixture to make the precursor mixture gellableand thus suitable for shaping. Various additives commonly used in thevarious shaping methods such as extrusion additives may be added to theprecursor mixture used for shaping.

Hydrotalcite-Like Materials and Methods of Making Same—Thermal Treatment

After shaping, the shaped bodies may optionally be submitted to athermal treatment. Such a treatment increases the physical strength ofthe particles. The thermal treatment can be conducted in anoxygen-containing atmosphere, in an inert atmosphere or in steam attemperatures varying from about 30° C. to about 900° C. for a timeranging from about a few minutes to about 24 hours. When, for instance,spray-drying a thermal treatment is inherently involved, a furtherthermal treatment may not be necessary.

Hydrotalcite-Like Materials and Methods of Making Same—Aging

In this step, the shaped bodies are immersed in a protic liquid orprotic gaseous medium. During the aging step crystallization tocrystalline anionic clay takes place. Suitable protic aging liquids orgaseous media are those liquids and gaseous media in which the shapedbodies do not dissolve, such as water, ethanol, methanol, propanol,steam, gaseous water, gaseous ethanol, and the like. Increasing thetemperature of the liquid and/or the pressure can reduce the aging time.The aging can also be conducted under autogeneous conditions. The agingtemperature may range from about 30° C. to about 500° C. The aging timecan vary from about 1 minute to several days, for instance about 7 days.For some purposes, it is advantageous to conduct several aging steps,optionally with intermediate drying steps, optionally followed bycalcination steps. For instance, an aging step with a temperature belowabout 100° C. may be followed by a hydrothermal aging step at atemperature above about 100° C. and autogeneous pressure, or vice versa.As will be described below in further detail, additives can be addedbefore, after or during any aging step. By adding specific anions to theaging medium the interlayer-charge balancing anions present may becontrolled. Examples of suitable anions are carbonates, bicarbonates,nitrates, chlorides, sulfates, bisulfates, vanadates, tungstates,borates, phosphates, pillaring anions such as V10O28-6, Mo7O24-6,PW12O40-3, B(OH)4-, B4O5(OH)4-2, HGaO3-2, CrO4-2, formates, acetate, andmixtures thereof. It is also believed that the presence of some of theseanions such as carbonate, bicarbonate, sulfate, and/or nitrate influencethe forming of side products such as brucite. For instance, the additionof ammonium hydroxide promotes meixnerite-like clay formation, whereasthe addition of ammonium carbonate promotes hydrotalcite-like clayformation.

For some applications, it is desirable to have additives present inand/or on the shaped bodies according to the invention, both metals andnon-metals, such as rare earth metals (especially Ce and La), Si, P, B,Group VI metals, Group VII metals, noble metals such as Pt and Pd,alkaline earth metals (for instance Ca and Ba) and/or transition metals(for example Mn, Fe, Ti, V, Zr, Cu, Ni, Zn, Mo, Sn). Said metals andnon-metals can be added separately or in mixtures in any of thepreparation steps of the invention. For instance, they can easily bedeposited on the shaped bodies before, during, or after aging, or elsethey can be added to the precursor mixture and/or any of the aluminum ormagnesium sources. Suitable sources of metals or non-metals are oxides,halides, or any other salt, such as chlorides, nitrates, phosphates, andthe like. As mentioned above, the metals and non-metals may be added inany of the preparation steps. This can be especially advantageous forcontrolling the distribution of the metals and non-metals in the shapedbodies. It is even possible to calcine the shaped bodies, rehydrate themand add additional additives.

With the help of additives, the shaped bodies may be provided withdesired functionalities, or the desired functionality may be increasedby the addition of additives. The suitability of anionic clay-containingshaped bodies for the removal of SOx and/or NOx compounds in FCC may beimproved by the addition of Ce and/or V. The presence of V and Znimproves the suitability for removal of S-compounds in the gasoline anddiesel fraction of FCC. As described above, these functionalities mayalso be built in by using and excess of aluminum source and/or magnesiumsource. A combination of these measures increases the effect.

The crystalline anionic clay-containing bodies may also be prepared tocontain conventional catalyst components such as matrix or fillermaterials (e.g. clay such as kaolin, titanium oxide, zirconia, alumina,silica, silica-alumina, bentonite, and the like), molecular sievematerial (e.g. zeolite Y, ZSM-5, and the like). Said conventionalcatalyst components may be added prior to the shaping step. Because theanionic clay is formed in situ, the resulting body will have ahomogeneous dispersion of anionic clay and catalyst components. With themethod according to the invention, multiple functional bodies can beprepared which can be used as a catalyst or as a catalyst additive.

The preparation process may be conducted batch-wise or in a continuousmode, optionally in a continuous multi-step operation. The process mayalso be conducted partly batch-wise and partly continuous.

If desired, the crystalline anionic clay-containing shaped bodiesprepared by the process according to the invention may be subjected toion exchange, in which the interlayer charge-balancing anions of theclay are replaced with other anions. Said other anions are the onescommonly present in anionic clays and include pillaring anions such asV10O28-6, Mo7O24-6, PW12O40-3, B(OH)4-, B4O5(OH)4-2, HBO4-2, HGaO3-2,CrO4-2. Examples of other suitable pillaring anions are given in U.S.Pat. No. 4,774,212. Said ion exchange can be conducted as soon as thecrystalline anionic clay has been formed.

Trapping Agent

A suitable trapping agent can comprise any of the following elements,ions thereof, or mixtures of such elements and/or ions thereof: barium,calcium, manganese, lanthanum, iron, tin, zinc, cerium, or any elementin Group 2, as identified in a Periodic Table of the Elements using thenew IUPAC format (i.e., current IUPAC format).

The trapping agent can be comprised of at least one of barium andcompounds of barium. It is presently believed that most forms of bariumare effective. Barium titanate and barium oxide are suitable bariumcompounds for use as the trapping agent. The barium compounds suitablefor use in the present invention can be organic or inorganic. Oil- andwater-soluble barium compounds are suitable. Suitable inorganic bariumcompounds include barium salts of mineral acids and basic bariumcompounds. Barium oxide is a suitable trapping agent. Examples ofsuitable barium salts are barium nitrate, barium sulfate, barium halidessuch as barium chloride, and barium oxyhalides, such as Ba(ClO₃)₂. Thehalogen-containing inorganic compounds are less preferred because oftheir corrosive effect on process equipment. Representative basic bariumcompounds suitable for use are barium hydroxide, barium hydrosulfide andbarium carbonate. Suitable organic barium compounds include the bariumsalts of carboxylic acids and barium-chelating agent complexes. Thebarium carboxylic acid salts can contain from about one to about 40carbon atoms per molecule and the acid moiety can be aliphatic or can bearomatic in nature. Representative compounds are barium acetate, bariumbutyrate, barium citrate, barium formate, and barium stearate. Suitablebarium complexes include complexes in which barium has been incorporatedby chelating agents such as 1,3-diketones, ethylene-diamine tetraaceticacid and nitrilotriacetic acid. Barium pentanedionate is a suitabletrapping agent.

Dispersion of Trapping Agent Onto the Outer Surface of Hydrotalcite

The trapping agent can be added to hydrotalcite while the hydrotalciteis being made according to the procedures described herein or accordingto other procedures now known or subsequently developed. Alternatively,the trapping agent can be added to existing hydrotalcite, for example,by pore volume impregnation or by use of a soluble barium source, aswill be familiar to those skilled in the art. Using any of thesemethods, at least a portion of the trapping agent will be dispersed onthe outer surface of the hydrotalcite.

While this invention is not limited to any particular amount of trappingagent on the outer surface of the hydrotalcite, in one compositionaccording to this invention, hydrotalcite having trapping agentdispersed on the outer surface thereon in the range of about 5 wt % toabout 35 wt %, or about 10 wt % to about 20 wt %, based on the totalweight of the trapping agent and the hydrotalcite, is useful.

Addition of Additive of this Invention to FCC

Compositions according to this invention can be added to an FCC unitwith the hydrocarbon feed, simultaneously with one or more catalysts, orafter the hydrocarbon feed and one or more catalysts have been added. Inone embodiment, composition according to this invention is combined withone or more FCC catalysts such that the weight percent of thecomposition according to this invention based on the total weight ofcomposition plus FCC catalyst(s) is from about 1 wt % to about 30 wt %,or about 2 wt % to about 20 wt %, or about 5 wt % to about 10 wt %.

EXAMPLES Example 1

Me-HTC (where Me designates Ba, Sr, Ca, Fe, Mn, Ce, La or Zn) accordingto this invention was made by introducing the Me component as a salt toa 4:1 molar ratio MgO:Al₂O₃ slurry (at 20 wt % solids) that had beenmilled and aged. The mixture containing Me, Mg and Al was thenspraydried to maintain an average particle size diameter around 75micrometers. This dried material was then calcined at 550° C. for 1 hourand rehydrated in a water slurry at 30° C. for 30 minutes. The resultantmixture was then dried and blended with commercial FCC catalyst at a 10wt % level. This blend was then evaluated in a fluidized bedmicro-reactor unit using a resid feed after a metallated deactivation.The blend was deactivated using a Mitchell impregnation route followedby steaming at 3000 ppm Ni and 3000 ppm V. Table 1 illustrates thebenefits of this invention. As compared to data generated with the useof the commercial FCC catalyst without the Me-HTC according to thisinvention, the coke yields are significantly reduced, while theconversion and gasoline yields are improved.

TABLE 1 CATALYST BASE BASE BASE BASE BASE BASE BASE BASE BASE BASE FCCFCC FCC FCC FCC FCC FCC FCC FCC FCC CAT- CAT- CAT- CAT- CAT- CAT- CAT-CAT- CAT- CAT- ALYST + ALYST + ALYST + ALYST + ALYST + ALYST + ALYST +ALYST + ALYST + ALYST Ba-HTC Sr-HTC Ca-HTC Fe-HTC Mn-HTC Ce-HTC La-HTCHTC Zn-HTC Yields at constant Conversion = 73% Catalyst-to-Oil wt/wt 5.92.8 3.4 3.6 3.1 3.4 3.5 4.4 4.6 4.9 Delta Coke, wt % 2.1 2.0 2.2 1.9 2.92.3 2.4 2.0 2.4 1.9 Coke 12.5 5.7 7.6 6.9 8.9 7.6 8.3 8.8 11.0 9.4 Drygas 5.8 4.7 5.0 5.3 5.2 5.1 5.3 5.3 5.5 5.4 Gasoline 41.7 46.1 45.1 44.643.8 44.5 44.1 43.9 42.3 43.7 Bottoms 9.7 10.2 10.4 10.5 10.3 10.9 10.410.6 11.2 10.3 Net Bottoms Conversion 77.7 84.1 82.0 82.6 80.8 81.5 81.380.5 77.8 80.2 Yields at constant CTO = 5 Conversion, wt % 70.5 80.877.7 77.1 77.8 78.3 77.0 74.7 74.3 73.3 Delta Coke, wt % 2.2 1.8 2.1 1.82.2 2.0 2.1 1.9 2.4 1.9 Coke 11.0 9.0 10.6 9.2 11.2 9.9 10.4 9.5 11.89.6 Gasoline 42.0 43.3 43.5 43.9 43.2 43.7 43.1 43.8 42.1 43.7 Bottoms11.6 6.4 7.8 8.1 7.8 7.8 8.2 9.5 10.3 10.2 Yields at constant Coke = 10%Conversion, wt % 68.7 82.2 76.9 78.3 75.4 78.5 76.3 75.9 70.8 73.9Gasoline 42.0 42.0 44.0 43.4 43.7 43.7 43.4 43.6 42.4 43.5 Bottoms 13.05.7 8.3 7.4 9.0 7.7 8.6 8.7 12.6 9.8

Example 2

Existing spraydried hydrotalcite was pore volume impregnated withbarium. SEM photos of the particles and cross-sections together withelement maps of Ba, Mg and Al show Ba on the outside surface of thehydrotalcite particles.

Example 3

Existing spraydried hydrotalcite was rehydrated in the presence ofbarium at 30 wt % solids for 30 minutes at 50° C., filtered and driedovernight at 110° C. SEM photos of the particles and cross-sectionstogether with element maps of Ba, Mg and Al show Ba on the outsidesurface of the hydrotalcite particles.

Example 4

Slurried MgO/CATAPAL was milled to 2.5 pore size diameter and aged for 2hours at 50° C. Barium nitrate was added, then the mixture wasspraydried, calcined, and rehydrated in H₂O, SEM photos of the particlesand cross-sections together with element maps of Ba, Mg and Al indicateBa distribution that is inferior to Examples 2 and 3.

The use of an additive of this invention is expected to result incatalysts with improved metals resistance, which is quite valuable forresid units.

While the present invention has been described in terms of one or morepreferred embodiments, it is to be understood that other modificationsmay be made without departing from the scope of the invention, which isset forth in the claims below.

1. A composition suitable for removing one or more poisonous metals fromhydrocarbons, said composition comprising hydrotalcite having one ormore trapping metals dispersed on the outer surface thereof, whereinsaid one or more trapping metals comprises manganese.
 2. The compositionof claim 1 wherein the hydrotalcite comprises naturally occurringhydrotalcite, synthetic hydrotalcite, or a hydrotalcite-like material.3. A method for removing one or more poisonous metals from hydrocarbonsin an FCC unit, the method comprising adding to the FCC unithydrotalcite having one or more trapping metals dispersed on the outersurface thereof, wherein said one or more trapping metals comprisesmanganese.
 4. A composition suitable for removing one or more poisonousmetals from hydrocarbons, said composition comprising a FCC catalyst anda hydrotalcite having one or more trapping metals dispersed on the outersurface thereof, wherein said hydrotalcite is prepared from sourcesselected from the group consisting of an aluminum source and a magnesiumsource, wherein said one or more trapping metals comprises barium, andwherein the amount of said hydrotalcite having one or more trappingmetals ranges from about 1 wt % to about 30 wt % based on the totalweight of said FCC catalyst and said hydrotalcite.
 5. A compositionsuitable for removing one or more poisonous metals from hydrocarbons,said composition comprising a FCC catalyst and consisting essentially ofhydrotalcite having at least one trapping metal dispersed on the outersurface thereof, wherein said hydrotalcite is prepared from sourcesselected from the group consisting of an aluminum source and a magnesiumsource, wherein at least one of the trapping metals is barium, andwherein the amount of said hydrotalcite having one or more trappingmetals ranges from about 1 wt % to about 30 wt % based on the totalweight of said FCC catalyst and said hydrotalcite.